Cloud Kit Framework Reference

The Cloud Kit framework provides interfaces for moving data between your app and your iCloud containers. You use Cloud Kit to take your app’s existing data and store it in the cloud so that the user can access it on multiple devices. You can also store data in a public area where all users can access it.

Using the Cloud Kit Framework

Cloud Kit is not intended as a replacement for your app’s existing data objects. Instead, Cloud Kit provides complementary services for managing the transfer of data to and from the cloud. Because it provides minimal offline caching support, Cloud Kit relies on the presence of the network and optionally on the device being configured with a valid iCloud account. A valid iCloud account is required only when you want to save data that is specific to a single user. Apps can always store data in a public area that is readable by all users.

Records are at the heart of all data transactions in Cloud Kit. A record is a dictionary of key-value pairs representing the data you want to save. You can add new keys and values to records at any time and you can create links between related records to organize your data. The CKRecord class defines the interfaces for managing the contents of records.

The classes of the Cloud Kit framework are not meant to be subclassed. You use these classes as-is to save, retrieve, and manipulate data in iCloud. In addition, many of the protocols of this framework are not intended to be adopted by classes outside of Cloud Kit and UIKit. Each protocol reference document includes information about whether you can adopt the protocol in your own classes. Cloud Kit also relies heavily on the use of NSOperation objects to manage the asynchronous transfer of data to and from the server.

Classes

Class	Abstract
`NSObject`	`NSObject` is the root class of most Objective-C class hierarchies.
`CKAsset`	A `CKAsset` object represents a large file associated with a record.
`CKContainer`	A `CKContainer` object encapsulates content associated with an app, including content that is publicly accessible to all users of the app and content that is private to a specific user.
`CKDatabase`	A `CKDatabase` object is a conduit for accessing the public and private data of an app container.
`CKDiscoveredUserInfo`	A `CKDiscoveredUserInfo` object contains information about a discoverable user in a database.
`CKNotification`	A `CKNotification` object represents a push notification that was sent to your app.
`CKQueryNotification`	A `CKQueryNotification` object represents a push notification that was generated by a subscription object.
`CKRecordZoneNotification`	A `CKRecordZoneNotification` object represents a push notification that was caused by changes to the contents of a record zone.
`CKNotificationID`	A `CKNotificationID` object uniquely identifies a push notification sent from a container.
`CKNotificationInfo`	A `CKNotificationInfo` object specifies the push notification data that the server sends to your app when a subscription finds a match.
`CKQuery`	A `CKQuery` object manages the criteria to apply when searching for records in a database.
`CKQueryCursor`	A `CKQueryCursor` object is an opaque data object that marks the stopping point for a query and the starting point for retrieving the remaining results.
`CKRecord`	A `CKRecord` object is a dictionary of key-value pairs that you use to fetch and save the data of your app.
`CKRecordID`	A `CKRecordID` object uniquely identifies a record in a database.
`CKRecordZone`	A `CKRecordZone` object defines an area for organizing related records in a database.
`CKRecordZoneID`	A `CKRecordZoneID` object uniquely identifies a zone in a database.
`CKReference`	A `CKReference` object creates a many-to-one relationship between records in your database.
`CKServerChangeToken`	A `CKServerChangeToken` object is an opaque data object that identifies a specific version of a record.
`CKSubscription`	You use a `CKSubscription` object to track changes occurring on the server.
`NSOperation`	The `NSOperation` class is an abstract class you use to encapsulate the code and data associated with a single task.
`CKOperation`	The `CKOperation` class is the abstract base class for all operations executed against a Cloud Kit database.
`CKDatabaseOperation`	The `CKDatabaseOperation` class is an abstract parent class for operations that act on the public or private databases in a container.
`CKFetchRecordChangesOperation`	A `CKFetchRecordChangesOperation` object reports on the changed and deleted records in the specified record zone.
`CKFetchRecordsOperation`	A `CKFetchRecordsOperation` object retrieves `CKRecord` objects (whose IDs you already know) from iCloud.
`CKFetchRecordZonesOperation`	A `CKFetchRecordZonesOperation` object retrieves `CKRecordZone` objects (whose IDs you already know) from iCloud.
`CKFetchSubscriptionsOperation`	A `CKFetchSubscriptionsOperation` object retrieves `CKSubscription` objects (whose IDs you already know) from iCloud.
`CKModifyRecordsOperation`	A `CKModifyRecordsOperation` object saves changes to one or more `CKRecord` objects.
`CKModifyRecordZonesOperation`	A `CKModifyRecordZonesOperation` object saves or deletes record zones.
`CKModifySubscriptionsOperation`	A `CKModifySubscriptionsOperation` object saves changes to one or more `CKSubscription` objects.
`CKQueryOperation`	A `CKQueryOperation` object is a concrete operation that you can use to execute queries against a database.
`CKDiscoverAllContactsOperation`	A `CKDiscoverAllContactsOperation` object retrieves the IDs of all discoverable users that are also in the user’s address book.
`CKDiscoverUserInfosOperation`	A `CKDiscoverUserInfosOperation` object retrieves the IDs for discoverable users whose email addresses or user record IDs you already know.
`CKFetchNotificationChangesOperation`	A `CKFetchNotificationChangesOperation` object retrieves `CKNotification` objects from a container.
`CKMarkNotificationsReadOperation`	A `CKMarkNotificationsReadOperation` object marks push notifications as read by your app so that they do not show up in future fetch results.
`CKModifyBadgeOperation`	A `CKModifyBadgeOperation` object updates the badge value applied to the app’s icon.
`NSSortDescriptor`	An instance of `NSSortDescriptor` describes a basis for ordering objects by specifying the property to use to compare the objects, the method to use to compare the properties, and whether the comparison should be ascending or descending.
`CKLocationSortDescriptor`	A `CKLocationSortDescriptor` object sorts records containing location data based on their distance from a location that you specify.

Protocols

Protocol	Abstract
`CKRecordValue`	The `CKRecordValue` protocol provides strong type checking for objects that the Cloud Kit framework stores on the server.

Other Reference

Reference
Cloud Kit Framework Constants Reference